BACKGROUND: Chronic pain is a major public health problem. More than 70 million Americans suffer from chronic pain and 50 million of them are disabled by pain. Chronic pain affects 40%- 70% of veterans and is a leading cause of disability, resulting in substantial negative impact on millions of veterans' lives. Chronic pain costs more than $100 billion per year in medical expenses, lost wages, and other costs. Musculoskeletal pain is especially common, accounting for two-thirds of all primary care visits for pain,and chronic low back pain is the most prevalent, disabling, and costly. Many options are available to treat CLBP, yet management is difficult because of the lack of consensus to guide clinician decisions. Analgesic medications remain the first line of treatment, but providers often do not use the entire array of analgesics that have been shown to be efficacious in CLBP. For non-pharmacological treatments, the strongest trial evidence is for those which use cognitive or behavioral approaches. Despite this evidence, primary care settings have not routinely implemented non-pharmacological treatments for CLBP because of time constraints, lack of provider knowledge, and limited personnel to deliver non- pharmacological treatments. However, the recent integration of psychologists into VA primary care settings increases the feasibility of administering non-pharmacological interventions. Use of opioid analgesics has increased both outside and within the VA for many pain conditions, including CLBP. While some pain experts view this trend as evidence of improved pain treatment, others have equated this practice to flying blind, given the paucity of trials evaluating the effectiveness and safety of opioids. Many patients continue to experience severe, disabling pain despite opioid treatment; others report intolerable side effects from opioids. Primary care providers often struggle with opioid treatment decisions and worry about fostering prescription drug abuse and addiction. Given these controversies, struggles, and lack of convincing data for opioid use, research to compare pharmacological and non-pharmacological treatments to improve the management of CLBP, especially for veterans on long-term opioid therapy, is urgently needed. OBJECTIVE: The CAre Management for the Effective use of Opioids (CAMEO) trial is a 2-arm randomized clinical trial to compare the effectiveness of pharmacological vs. behavioral approaches for CLBP. The study aims are: 1) to compare the interventions' (PHARM vs. BEH) effects on pain intensity, function, and other pain relevant outcomes at 6 months (primary end point) and 12 months (sustained effect); and 2) to compare the cost-effectiveness of the interventions METHODS: Our study sample will include veterans with moderate to severe CLBP despite long- term opioid therapy. Patients from the five primary care clinics at the Roudebush VA Medical Center and two community based outpatient clinics will be recruited to participate in CAMEO and randomized to one of two treatment arms. The pharmacological arm will involve guideline- concordant opioid management coupled with algorithm-based co-analgesic treatment (PHARM). Patients in the behavioral arm (BEH) will receive pain coping/self-management skills training. The trial will last 12-months and all participants will undergo comprehensive outcome assessments at baseline, 3, 6, 9, and 12 months.